Separate lubricating system for marine propulsion device

ABSTRACT

Several embodiments of separate lubricating systems for two-cycle internal combustion engines and particularly those of outboard motors. In each embodiment, the lubricating system includes a relatively large lubricant storage tank that is adapted to be carried in the hull of the associated watercraft and a relatively small lubricant delivery tank carried by the engine of the outboard motor. A pump is provided for transferring lubricant from the storage tank to the delivery tank and warning devices are incorporated to indicate when the level in each of the tanks falls below a predetermined value. Furthermore, the transfer pump is disabled upon the falling of the level of the liquids in the storage tank below a predetermined value. The pump is positioned in proximity to this storage tank and is juxtaposed and plumbed in such a way that it will not pick up foreign particles from the bottom of the tank, but will always have its inlet and outlet subject to liquid so that the pump will not run dry. A system is provided for disabling the pump if the motor is tilted up and the delivery tank is vented in such a way that lubricant will not be spilled when the engine is tilted up and regardless of its angular position. Several embodiments of arrangments are disclosed for delivering lubricant from the delivery tank to the various components of the engine.

This is a division of application Ser. No. 797,977, filed Nov. 14, 1985,now U.S. Pat. No. 4,615,305, which is a division of Ser. No. 610,847,filed May 16, 1984, now U.S. Pat. No. 4,572,120.

BACKGROUND OF THE INVENTION

This invention relates to a separate lubricating system for marinepropulsion device and more particularly to an improved lubricatingsystem for a two-cycle engine, and particularly that of an outboardmotor.

With two-cycle internal combustion engines, it has been the generalpractice to lubricate the engine by mixing lubricating oil with the fuelmixture. Although such arrangements offer extreme simplicity, the mixingof lubricating oil with the fuel can be troublesome to the user of theengine. In addition, the requirement for mixing lubricant with the fueland lubricating the components of the engine with the fuel/air mixturedoes not always insure the adequate amount of lubrication to the variouscomponents to be lubricated under all running conditions. In order toobviate some of these difficulties, it has been proposed to provide alubricating system where the lubricant is contained within a separatetank from the fuel and is supplied to the engine during its running.Such arrangements have a number of advantages.

When the engine in question constitutes the power unit of an outboardmotor, however, the provision of such separate lubricating systems cangive rise to certain problems. Due to the relatively compct nature of anoutboard motor, it is difficult to provide the necessary lubricantstorage capacity within the confines of the motor. That is, it isdesirable that the lubricant system contain sufficient lubricant forlong running periods. However, it is difficult to provide an adequatelubricant storage system within the cowling of an outboard motor forsuch extended running periods. Although these problems may be overcomethrough the use of a lubricating system wherein the lubricant is storedexternally of the engine, such external storage systems themselves giverise to certain problems. For example, it is necessary to deliver thelubricant from a remote location to the engine immediately upon startupand even during cranking so as to ensure adequate lubrication duringthis extremely critical running condition. Such remotely positionedlubricant tanks, however, make it difficult to ensure adequatelubrication during startup. Therefore, it has been proposed to use alubricating system wherein the engine mounts a relatively smalllubricant delivery tank and lubricant is delivered to this lubricantdelivery tank from a remotely positioned lubricant storage tank. Anarrangement is provided wherein a substantially constant head oflubricant is maintained in the lubricant delivery tank so as to ensureadequate lubrication under all running conditions. An example of such alubricating system is shown in U.S. Pat. No. 4,403,578, entitled"Separate Lubricating System For Outboard Engine", issued Sept. 13, 1983in the name of Tomio Iwai and assigned to the assignee of thisapplication. Although systems of this type have great utility andovercome many of the disadvantages of prior art two-cycle enginelubricating systems, still further improvements are desirable. Forexample, it is desirable to provide a system wherein a warning is givento the engine operator if the amount of lubricant in the storage tankfalls below a predetermined amount so that the lubricant in the storagetank may be replenished.

It is, therefore, a principal object of this invention to provide animproved lubricating system for a two-cycle internal combustion engine.

It is a further object of this invention to provide an improvedlubricating system for an outboard motor that embodies a remotelypositioned lubricant storage tank and an engine-mounted lubricantdelivery tank with a device for transferring lubricant from the storagetank to the delivery tank and further including means for providing awarning when the amount of lubricant in the delivery tank falls below apredetermined value.

In addition to providing a warning when the amount of lubricant in thestorage tank falls below a predetermined amount, it is also desirablewith lubricating systems of this type to provide some means for insuringagainst the complete depletion of the amount of lubricant in the systemduring long cruising periods.

It is, therefore, a still further object of this invention to provide animproved lubricating system for a two-cycle engine in which thedepletion of lubricant from the separate lubricating system can beavoided during long running periods.

It is a further object of this invention to provide a system forreducing engine speed to conserve lubricant when the amount of lubricantin the separate lubricating system falls below a predetermined value.

As has been noted, there are a number of advantages in providing aseparate lubricating system for an internal combustion engine of thetwo-cycle type that employs a relatively small lubricant delivery tankmounted on the engine and a larger lubricant storage tank that isremotely positioned and which is adapted to supply lubricant to theengine-mounted lubricant delivery tank. Such lubricating systems haveparticular utility in connection with outboard motors. It is alsodesirable to provide the operator with an indication or warning when thelubricant in either of the tanks falls below a predetermined value. Forexample, if the lubricant in the delivery tank falls below apredetermined value and there is still adequate lubricant in the storagetank, the operator will know that there is some fault in the system fordelivering lubricant from the storage tank to the delivery tank. On theother hand, if the amount of lubricant in the storage tank falls below apredetermined value and there is still adequate lubricant in thedelivery tank, the operator will know that it is time to replenish thelubricant in the storage tank, but also will be confident that there isadequate lubricant available to lubricate the engine for a period oftime.

It is, therefore, a still further object of this invention to provide alubricating system for a two-cycle internal combustion engine thatembodies a lubricant delivery tank and a lubricant storage tank andmeans for providing an indication to an operator when the level ineither tank falls below a predetermined amount.

The advantages of separate lubricating systems for two-cycle outboardmotors incorporating a small lubricant delivery tank mounted internallywithin the cowling of the outboard motor and a remotely positionedlubricant storage tank have been stressed. Such systems should employ anarrangement for pumping lubricant from the storage tank to the deliverytank when the level of lubricant in the delivery tank falls below apredetermined amount. However, it is the normal practice to mountoutboard motors for tilting about a horizontally disposed axis from anormal running condition to either a trim up or a tilted upout-of-the-water position. If the lubricant delivery tank is mounted onthe outboard motor and the motor is tilted up, the lubricant in thedelivery tank will flow to another orientation which may give a lowlevel indication that could cause further lubricant to be delivered fromthe storage tank to the delivery tank. This would be undesirable whenthe outboard motor is tilted up since the delivery tank would beoverfilled when the motor was again tilted down.

It is, therefore, a still further object of this invention to provide animproved lubricating system for an outboard motor which insures againstthe overfilling of the lubricant delivery tank when the motor is in atilted up condition.

In conjunction with the use of separate lubricating systems andparticularly those for outboard motors that employ a relatively smalllubricant delivery tank mounted by the engine and periodicallyreplenished from a remotely positioned storage tank, it is necessary toprovide some arrangement for venting the area above the lubricant in thedelivery tank to the atmosphere so as to compensate for changes in theamount of lubricant in the tank. Although such venting may beconveniently performed by means of a pressure responsive check valve atan upper level in the tank, the fact that the outboard motor is tiltableabout a horizontally disposed axis, as aforenoted, somewhat complicatesthe venting arrangement. Furthermore, the fact that the outboard motoris also steerable about a vertically extending axis and may tilted upwhen steered to either an extreme right or lefthand position can furthercomplicate matters. Unless the venting system is properly arranged, thetilting up of the motor can cause the lubricant to be discharged throughthe venting system and foul the motor and the surrounding area.

It is, therefore, a still further object of this invention to provide animproved venting system for a separate lubricating system for atwo-cycle internal combustion engine.

It is a further object of this invention to provide an improved ventingsystem for an outboard motor embodying a motor-mounted lubricantdelivery tank that will insure against the spillage of lubricantregardless of the orientation of the motor.

In separate lubricating systems of the type embodying an engine-mountedlubricant delivery tank and a remotely positioned lubricant storage tankwith a pumping device for pumping lubricant from the storage tank to thedelivery tank, it has been the practice to mount the pump in or inproximity to the storage tank so as to insure that it will always beprimed and available to pump lubricant to the delivery tank whenrequired. If the pump is mounted externally of the storage tank and at alow level, it is likely to become contaminated and damaged by the debriswhich may accumulate in the bottom of the hull of the watercraft.Although these problems can be avoided by mounting the external pump ata higher level, this can itself cause problems. If the pump is notmounted at the lowest level in the tank, there may be situations whereinthe pump will cavitate when the oil level in the tank falls to a pointwhere it is at or near the level of the lubricant pump. Such cavitationcan cause damage to the pump and other problems.

It is, therefore, a further object of this invention to provide animproved separate lubrication system for a two-cycle engine wherein pumpcavitation may be avoided.

It is a further object of this invention to provide an improved pumpingarrangement for the storage tank of a separate lubricating system of thetype described that insures against damage to the pump by cavitation.

As has been noted, the mixing of lubricant with the fuel has been a wellknown method for lubricating two-cycle internal combustion engines. Theinduction systems for such engines normally cause the fuel and lubricantto pass across most, if not all, of the components of the engine to belubricated. Thus, even if a separate lubricating system is incorporatedwhich does not employ the mixing of lubricant directly with the fuel inthe fuel storage tank, it has been the practice to inject lubricant intothe induction system so that it will mix with the intake charge and bedelivered to the various components of the engine. Such arrangementshave the advantage of permitting more accurate control over the amountof lubricant delivered, but also have the advantage of not requiring theoperator to mix the lubricant with the fuel. However, this type ofinduction system and lubricating system does not always insure adequatelubrication of all components of the engine.

It is, therefore, a still further object of this invention to provide animproved lubricating system for a two-cycle internal combustion enginewhich offers simplicity and, at the same time, insures the adequateamount of lubrication of all components of the engine.

In connection with the use of separate lubricating systems for internalcombustion engines of the two-cycle type, it is normally the practice toemploy some form of pump for delivering lubricant, even when thelubricant is delivered merely to the induction system for mixing withthe fuel/air intake charge. However, as has been noted, the amount oflubricant required by the various components of the engine may vary.

It is, therefore, a still further object of this invention to provide animproved lubricating system for a two-cycle internal combustion enginewherein portions of the lubricant are delivered to the engine underpressure and other portions are delivered in a non-pressurized manner.

SUMMARY OF THE INVENTION

A number of features of the invention are adapted to be embodied in alubricating system for a two-cycle internal combustion engine thatcomprises a relatively large remotely positioned lubricant storage tank,a relatively small lubricant delivery tank positioned in proximity tothe engine for delivering lubricant to its lubricating system and meansfor transferring lubricant from the storage tank to the delivery tank.

In accordance with a first feature of the invention as embodied in sucha lubricating system, means are incorporated for providing a warningsignal when the level of lubricant in the storage tank falls below apredetermined amount.

In accordance with another feature of the invention as applied to such alubricating system, means are provided for reducing the speed of theengine when the level of the lubricant in one of the tanks falls below apredetermined value for extending the running period with the availablelubricant.

In accordance with another feature of the invention as adapted to beembodied in such a lubricating system, means are incorporated forproviding a first signal when the level of lubricant in one of the tanksfalls below a predetermined level and means are also provided forproviding a second signal when the level of lubricant in the other ofthe tanks falls below a predetermined level so that the operator candetermine the cause of the depletion of lubricant.

Another feature of the invention is adapted to be embodied in alubricating system of the type described for the two-cycle engine of anoutboard motor that is tiltable about a horizontally extending axis andin which the lubricant delivery tank is mounted by the tiltable part ofthe outboard motor. In accordance with this feature of the invention,means are provided for insuring against the transfer of lubricant fromthe storage tank to the delivery tank when the outboard motor is tiltedup.

A still further feature of the invention is adapted to be embodied in alubricating system for an outboard motor as described in the preceedingparagraph. In accordance with this feature of the invention, means isprovided for venting the delivery tank and the venting means ispositioned above the level of lubricant to the delivery tank regardlessof the tilted position of the outboard motor.

Yet another feature of the invention is also adapted to be embodied in alubricating system of the type described wherein the means fortransferring the lubricant from the storage tank to the delivery tankcomprises a pump that is located in proximity to the storage tank andabove the lower wall of the storage tank. In accordance with thisfeature of the invention, conduit means extend from the outlet of thepump to the delivery tank and a trap is formed in the conduit means formaintaining lubricant in proximity to the pump outlet for precludingcavitation of the pump.

Yet another feature of the invention is adapted to be embodied in alubricating system of the type described. In accordance with such asystem, there are first lubricant means that deliver lubricant from thedelivery tank to the induction system of the engine for induction intothe engine induction system to lubricate at least some of the enginecomponents and second lubricating means for delivering lubricant fromthe delivery tank to other components of the engine independently of theinduction system.

A still further feature of the invention is adapted to be embodied in alubricating system of the type described. In accordance with thisfeature of the invention, a lubricant pump is provided that has an inletwhich is in communication with the delivery tank. First lubricatingmeans delivers lubricant from the lubricant pump to certain componentsof the engine for lubricating those certain components. Secondlubricating means extend directly from the delivery tank to at leastanother component of the engine for lubricating that other componentindependently of the lubricating pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic side elevational view of a watercraftand associated outboard motor having a separate lubricating systemconstructed in accordance with a first embodiment of the invention.

FIG. 2 is an enlarged side elevational view of the power head of themotor showing further details of the construction of the lubricatingsystem.

FIG. 3 is an enlarged side elevational view, with portions broken away,of the lubricant storage tank.

FIG. 4 is an enlarged side elevational view, with portions broken away,of the lubricant delivery tank.

FIG. 5 is a schematic electrical diagram of the control and warningsystem.

FIG. 6 is a schematic electrical diagram showing the engine ignition andspeed control system.

FIG. 7 is a diagramatic representation explaining the operation of theengine speed control system.

FIG. 8 is an enlarged cross-sectional view showing the tilt sensingswitch in the normal running condition.

FIG. 9 is an enlarged cross-sectional view, in part similar to FIG. 8,showing the tilted up condition.

FIG. 10 is an enlarged side elevational view, in part similar to FIG. 2,showing another embodiment of the invention.

FIG. 11 is a side elevational view of the engine, with a portion brokenaway, of the embodiment of FIG. 10.

FIG. 12 is an enlarged side-elevational view, in part similar to FIGS. 2and 10, showing a further embodiment of the invention.

FIG. 13 is a partially schematic side elevational view of a watercraftand outboard motor constructed in accordance with a yet furtherembodiment of the invention.

FIG. 14 is an enlarged side elevational view of the power head of theoutboard motor shown in FIG. 13.

FIG. 15 is an enlarged side elevational view of the power head shown inFIG. 14 looking from the opposite side.

FIG. 16 is a top plan view of the power head of this embodiment.

FIG. 17 is an enlarged side elevational view, with a portion brokenaway, of a lubricant delivery tank having a venting constructionconstructed in accordance with an embodiment of the invention.

FIG. 18 is a top plan view of the lubricant delivery tank shown in FIG.17.

FIG. 19 is a partial cross-sectional view showing another embodiment ofventing system for a lubricant delivery tank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment of FIGS. 1through 9

Referring first to the embodiment of FIGS. 1 through 9 and intially toFIG. 1, an outboard motor having a separate lubricating systemconstructed in accordance with an embodiment of the invention isidentified generally by the reference numeral 21. The outboard motor 21is adapted to be mounted on the transom of an associated watercraft,shown partially schematically and indicated generally by the referencenumeral 22 in a known manner. This mounting arrangement permits steeringmovement of the outboard motor 21 about a vertically extending steeringaxis and tilting movement about a generally horizontally extending tiltaxis between a normal running condition, a plurality of trim adjustedpositions and a tilted up, out-of-the-water position.

The outboard motor 21 includes a power head consisting of an internalcombustion engine 23 which, as will be noted, is of the crankcasecompression two-cycle type and which may have any type of cylinderconfiguration. In order to more clearly show the construction, theprotective cowling which normally encircles the internal combustionengine 23 has been removed and is not shown in the drawings. The motor23 includes a driven crankshaft, which is illustrated in certain of theremaining figures, which in turn drives a drive shaft that extendsthrough a drive shaft housing 24 and which drives a propeller 25 in asuitable manner, which may include via a forward/reverse/neutraltransmission. The motor 23 includes an induction system consisting ofone or more carburetors 26 that receive air from an air intake device 27and fuel from a remotely positioned fuel tank 28 in a known manner fordelivery to the individual crankcases of the engine 23 through an intakemanifold 29 and appropriate read valves (not shown). This generalconstruction of the outboard motor and its induction system is not shownin any detail because it may be of any conventional type.

In accordance with the invention, the outboard motor 21 and specificallyits engine 23 is provided with a separate lubricating system so that itwill be unnecessary for the operator to mix lubricant with the fuelsupplied to the fuel tank 28. This separate lubricating system iscomprised of a relatively large lubricant storage tank 31 that isadapted to be positioned within the hull of the watercraft 22. Thelubricating system further includes a relatively small lubricantdelivery tank 32 that is mounted directly to the outboard motor 23, in amanner to be described, and which is positioned within the protectivecowling of the power head. Lubricant is delivered from the lubricantdelivery tank 32 to a lubricant pump 33 through a conduit 34. Thelubricant pump 33 then transfers the lubricant under pressure through aplurality of conduits 35 to each of the individual runners of the intakemanifold 29 that serve the respective crankcase chambers of the engine23. Since, in the illustrated embodiment, the engine 23 is of the V-4type, there are four lubricant delivery conduits 35 each extending fromthe lubricant pump 33 to a respective one of the runners of the intakemanifold 29.

Referring now additionally to FIG. 3, the lubricant storage tank 31, ashas been noted, has a relatively large capacity and is adapted to bepositioned in the hull of the watercraft 22. Lubricant is delivered fromthe storage tank 31 to the delivery tank 32 by means of a pump 36 thatis mounted externally of the tank 31 in a suitable manner. The pump 36is of the positive displacement type and has a pumping cavity 37 inwhich intermeshing gears 38 are positioned. The gears 38 are driven byan electric motor which is not shown in this figure, but which isindicated by the reference numeral 39 in the schematic wiring diagramFIG. 5. Lubricant is delivered to the pumping cavity 37 by a lubricantdelivery line 41 that extends to an inlet nipple 42 that is positionedin a lower wall of the lubricant storage tank 31. The lubricant pumpdischarges from its pumping cavity 37 through a delivery conduit 43 thatextends to the lubricant delivery tank 32. In accordance with a featureof the invention, the delivery conduit 43 is provided with a U-shapedtrap 44 so as to insure the presence of lubricant at both the inlet andoutlet sides of the pump 36 even when the level of lubricant in the tank31 is at a low condition. This level is shown by the broken line 45 inFIG. 3. It should be noted that the lubricant pump 36 is above thislevel. The pump 36 is positioned above the bottom of the storage tank 31so that it is less likely to be contaminated by debris which mayaccumulate on the floor of the hull of the watercraft 22. Even thoughthe pump 36 is positioned above the lower level of the tank 31, the trap44 insures that a level of lubricant to the line 45 will also bemaintained in the outlet and inlet sides of the pump 36 so that if thepump is operated even with the lubricant at the level 45, the pump willnot run dry.

The storage tank 31 is provided with a filler neck 46 that is closed bya cap 47 so that the quantity of lubricant in the tank 31 may beperiodically replenished. A check valve type air relief or venting valve48 is positioned in the cap 47 so as to permit air to be admitted to thetank 31 as the level of lubricant falls during operation.

A sensing device, indicated generally by the reference numeral 49, isprovided so as to issue a caution signal, in a manner to be described,when the level in the tank 31 falls to or below the level 45. Thissensing device 49 is carried by a cap-like member 51 that is received ina threaded opening 52 in an upper wall of the tank 31. A support rod oftubular configuration 53 extends from the cap-like member 51 into theinterior of the tank 31 and carries an annular shell 54 at its lowerend. Contained within this annular shell is a float 55 that is moveablefrom an uppermost position to a lowermost position. The float 55 has ametallic sleeve 56 that is adapted to cooperate with a sensing member orswitch 57 carried by the tube 53 so as to close a circuit, in a mannerto be described, as long as the level of lubricant in the storage tank31 is above a predetermined level. If, however, the level falls belowthe level indicated by the line 45, the metallic sleeve 56 will move outof contact with the switch 57 and this switch will then be opened.

It should be noted that the shell 54 is positioned at the lowermostportion of the tank 31 and thus the float 55 can never rise above theline 45. In addition, restricted openings 58 extend through the wall ofthe shell 54 so as to permit lubricant to enter the interior of theshell at a somewhat restricted rate. This will insure that the float 55will not cause inadvertent opening of the switch if the level oflubricant in the tank 31 is low, but nevertheless varies due to suddenmaneuvering of the watercraft 22. In this way, false caution signalswill be avoided.

Referring now additionally to FIG. 4, the construction of the lubricantdelivery tank 32 and its associated components will be described. Thelubricant delivery conduit 44 communicates with a quick disconnectcoupling 59 (FIG. 1) that is connected to an inlet nipple 61 formed inthe upper side of the lubricant delivery tank 32. The delivery tank 32is, in turn, mounted on the cylinder block of the engine 23 by meansincluding a mounting bracket 62 and bolt 63 (FIG. 2). The lower end ofthe lubricant delivery tank 32 is provided with an outlet nipple 64 towhich the conduit 34 is connected so as to transfer lubricant from thedelivery tank 32 to the lubricant pump 33.

A sensing and control device, indicated generally by the referencenumeral 65, is provided which is mounted in a neck opening 66 formed inan upper surface of the delivery tank 32. The sensing device 65 includesa cap 67 from which depends a tubular member 68 having a central tube69. An annular float 71 encircles the tube 69 and is contained withinthe tubular member 68. A plurality of restricted openings 72 are formedin the wall of the tubular member 68 and in its lower surface so as topermit restricted communication of the lubricant in the delivery tank 32with the interior of the tubular member 68 so that the float 71 willmove to a level that is determined by the level of fluid in the tank 32.The restricted openings 72 function like the restricted openings 58 inthe tubular member 54 of the storage tank 31 ao as to preventinadvertent signal transmission due to short variations in liquid levelcaused by sharp maneuvers of the boat 22.

The float 71 is formed with an annular inner sleeve 73 that is adaptedto cooperate with one of three switching elements 74, 75 and 76 so as toprovide control and warning signals. The switch 74, as will becomeapparent, provides a signal when the level of lubricant in the supplytank 32 is at a maximum line, indicated by the broken line 77, so as todiscontinue operation of the motor 39 and pump 36. The switch 75cooperates with the sleeve 73 so as to provide a signal when thelubricant level reaches a lower level indicated by the line 78 so as toinitiate operation of the motor 39 and pump 36 so as to replenish thelubricant in the delivery tank 32. The switch 76 cooperates with thesleeve 73 so as to provide a warning signal when the lubricant levelreaches a low level indicated by the line 79 in a manner which will bedescribed.

In order to permit air to enter and leave the delivery tank 32 inresponse to changes in liquid level therein, its upper wall is formedwith an upwardly extending recess 81 and check valves 82 and 83 areprovided which communicate the recess 81 with the atmosphere so as topermit air to flow in a controlled manner in and out of the supply tank32. The valve 83 permits air to enter and the valve 82 permits air toexit.

Referring now additionally to FIG. 2, the lubricant pump 33 has an inletnipple 84 that communicates with the conduit 34 so that lubricant willbe delivered by gravity from the delivery tank 32 to the pump 33. Thepump 33 has a driving shaft to which a worm gear 85 is affixed. The wormgear 85 is enmeshed with a worm wheel 86 that is fixed for rotation withthe lower end of the previously mentioned crankshaft 87 immediatelyabove its driving connection with the drive shaft 88. Hence, thelubricating pump 33 is driven in response to the rotation of thecrankshaft 87.

The output of the lubricating pump 33 is adjusted in response tothrottle position and for this purpose a lever 89 is affixed to thethrottle valve shaft of one of the carburetors 26. The lever 89 ispivotally connected to one end of a link 91, the other end of which ispivotally connected to a control lever 92 of the pump 33. Hence,movement of the carubretor throttle valves will, through the lever 89,link 91 and control lever 92, appropriately control the amount oflubricant delivered from the pump 33 to the manifold runners through theconduits 35.

The electrical control system for the lubricating system and itsinterrelationship to the engine speed control will now be described. Thecontrol circuit is depicted schematically in FIGS. 5 and 6 and includesa number of components that are positioned within a control box,indicated generally by the reference numeral 93 and which is mounted onthe cylinder block of the engine 23 by means of a bolt or the like 94(FIG. 2). Contained within the control box 93 is an engine positionsensing device, indicated generally by the reference numeral 95 andshown in most detail in FIGS. 8 and 9. The engine position sensingdevice 95 is a mercury type switch and includes a body 96 in which aglobule of mercury 97 is contained. The body 96 is closed by aninsulating cap 98 from which a pair of terminals 99 and 101 extend. Whenthe outboard motor 21 is in its normal running condition, as shown inFIGS. 1 and 8, the glubule of mercury 97 will be spaced from theterminals 99 and 101 and the circuit will then be open. However, whenthe motor 21 is tilted up, the sensing device 95 will be rotated to theposition shown in FIG. 9 and the mercury globule 97 will close thecircuit between the terminals 99 and 101.

Referring now additionally to FIG. 5, the system includes a panel 102(FIG. 1) that is positioned in the watercraft 22 and which includes agreen, system on light 103, a yellow warning light 104 and a red cautionlight 105. In addition, the panel 102 further carries a warning buzzer106 that provides an audible warning under the caution condition, aswill become apparent.

The circuit, as shown in FIG. 5, includes a power source such as abattery 107 that has one side grounded and its other side connected to amain power control switch 108, which may also be juxtaposed on the panel102, if desired. Closure of the switch 108 will energize the points P1,P2, P3, P4 and P5 through suitable junctions (not shown). When the maincontrol switch 108 is closed and if there is sufficient lubricant in thestorage tank 31, the switch consisting of the contact 57 and floatcontrolled sleeve 56 will be closed and the green "on" light 103 will beilluminated.

Assuming that that level of lubricant in the delivery tank 32 is alsoadequate so that the float 71 will be positioned between the contacts 74and 75, these contacts 74 will be open as shown in FIG. 5. Under thiscondition, a flip flop 109 will be maintained in a "1" condition so thatthe power delivered to its one terminal through a diode 111 and resistor112 and the power delivered to its other terminal from the point P1through a resistor 113 will put an output voltage through a resistor 114to the gate of a transistor 115 so that the transistor 115 will bemaintained in an "on" condition. When the transistor 115 is on, thecircuit containing resistor 116 will be grounded and the gate of thetransistor 117 will be negative so that the transistor 117 will be offand no voltage will be supplied to the motor 39 and the pump 36 will notbe operated. It should be noted that a diode 118 is positioned acrossthe circuit of the motor 39.

As the motor 21 and specifically its internal combustion engine 23continues to operate, the lubricant pump 33 will deliver lubricant fromthe delivery tank 32 to the engine induction system through the deliveryconduits 35. This will cause the level of lubricant in the delivery tank32 to be gradually depleted until it reaches the level 78 (FIG. 4). Atthis time, the sleeve 73 will come into registry with the switch 75 soas to close its circuit. The source P1 will now discharge through theresistor 113 to ground and change the state of the flip flop 109 to its"0" state. When this occurs, the gate of the transistor 115 is affectedso as to turn the transistor "off". Turning of the transistor 115 offchanges the state of the gate of the transistor 117 and it will now turn"on" closing the circuit through the motor 39 so as to energize it andthe pump 36.

As the pump 36 begins to operate, lubricant will be drawn from thesupply tank 31 and delivered to the delivery tank 32 through the conduit41. As the lubricant is delivered, the float 71 will raise and againmove the sleeve 73 out of registry with the switch 75 so as to open it.However, this will not change the state of the flip flop 109 and thetransistor 115 will be maintained switched "off" and the transistor 117will be maintained switched "on" so that the motor 39 and pump 36 willcontinue to operate.

As the level in the delivery tank 32 continues to increase, it willeventually reach the level 77 (FIG. 4) and bring the sleeve 73 intoregistry with the switch 74. This switch will now close and shunt theline bearing the resistor 112 to ground and thus change the state of theflip flop 109 back to its "on" state. This will cause the transistor 115to be switched on and the transistor 117 to be switched off so that themotor 39 and pump 36 are turned off. The level of lubricant in thedelivery tank 32 will then again begin to deplete and this cycling ofthe motor 39 and pump 36 as described will continue during the operationof the motor 21 and specifically its engine 23.

It should be noted that if for some reason the motor 21 is tilted upfrom its normal condition, the position responsive switch 95 will closeso that the transistor 117 cannot be turned on and the motor 39 and pump36 will not be energized even if the contact 75 is opened. Also, thegreen light 103 will be maintained in its illuminated condition duringthis entire operation.

If, during long periods of cruising, the lubricant in the supply tank 31becomes depleted below the minimum desired line 45, the float 55 willmove downwardly so that its sleeve 56 no longer contacts the switch 57and thus will, in effect, open this otherwise normally closed switch.When the switch 57 is closed, current from the source P2 will go to theground through this switch through a resistor 119 and diode 121. In alike manner, current from the source P3 will go to ground through theresistor 122 and diode 123. However, when the switch 57 opens due tolowering of the float 55, a protecting resistor 124 across the switch 57offers sufficient resistance so as to cause the power from the source P3to be delivered through a resistor 125 to the gate of a transistorswitch 126 to turn this normally closed switch on and render itconductive. When the transistor switch 126 is switched on, current fromthe source P4 flows through the yellow caution light 104 and will causeit to become illuminated. Thus, the operator of the watercraft 22 willreceive a warning indicating that the lubricant level in the supply tank31 is low and that it should be replenished.

Opening of the switch 57 also causes current from the source P2 to nolonger flow through the diode 121 due to the high resistance of theresistor 124. Therefore, current from the source P2 will flow throughthe resistor 119 and a diode 127 to ground through a resistor 128 so asto switch the transistor 115 on and the transistor 117 off so that theoperation of the motor 39 and pump 36 will also be discontinued.

It should be noted that the yellow caution light 104 is switched on andthe motor 39 and pump 36 automatically stopped before the level oflubricant in the supply tank 31 falls to its fully depleted condition.Thus, the caution light 104 will go on before the lubricant in thesupply tank 31 is depleted and at a time when the level of the lubricantin the delivery tank 32 is above its level 78. Therefore, adequatewarning of a low supply lubricant condition will be given to theoperator.

In the event of emergency conditions the operator may switch on themotor 39 and pump 36 so as to transfer the remaining lubricant from thestorage tank 31 to the delivery tank 32. This is done by closing amanual override switch 129 in the circuit of the motor 39 which thencauses the motor to operate independently of the condition of thetransistor switch 117.

Assuming that the level of lubricant in the supply tank 31 has fallenbelow the line 45 and the motor 21 is continued to be operated, thelevel of lubricant in the delivery tank 32 will, of course, continue tobe depleted. When the level falls to the line 79, which is still abovethe point when the amount of lubricant in the delivery tank 32 iscompletely exhausted, the float sleeve 73 will register with the switch76 and will turn it on. When the switch 76 is switched on andremembering that the switch 57 is switched off, current from the sourceP3 may flow through a diode 131 to the ground through the closed switch76. As a result, the transistor 126 is again switched off and the yellowcaution light 104 will also be switched off. It should be noted thatthere is a high resistance protective resistor 132 positioned across theswitch 76 to protect it from arcing upon opening of the switch.

When the switch 76 is closed, a circuit from the source P5 through thewarning buzzer 106 will be completed to the ground through the switch 76and a diode 133. This will cause the buzzer 106 to give an audiblewarning to the operator. In addition, closure of the switch 76 willcomplete the circuit from the source P4 through the red warning light105 to the ground and this also will be illuminated.

In addition to providing the audible and visual warning by sounding ofthe buzzer 106 and illuminating the red warning light 105, closure ofthe switch 76 also enables an engine speed control circuit, indicatedgenerally by the reference numeral 134, so as to reduce the speed ofoperation of the engine 23 and to conserve the remaining lubricant inthe delivery tank 32. The circuit 134 has a connection 135 to the sourceP5 through the buzzer 106. The details of the protective speed controlcircuit 134 may be best understood by reference to FIG. 6, wherein thiscircuit is shown schematically. In addition, FIG. 7 is a graphicalexplanation of the operation of the circuit.

The ignition system for the engine 23 includes a magneto generator,indicated generally by the reference numeral 136, which may be of anyknown type and which includes a charging coil 137 and a pulser coil 138.The charging coil 137 and pulser coil 138 provide their signals andcharges to a CD ignition circuit, indicated generally by the referencenumeral 139.

The CDI circuit 139 includes a charging capacitor 141 that is chargedfrom the charging coil 137 through a rectifying diode 142 to a polarityas shown in FIG. 6. A charge will be built up on the capacitor 141during rotation of the engine crankshaft until an appropriate trippingdevice such as a rotating magnet causes a voltage to be generated in thepulser coil 138 to indicate that the crankshaft is in the appropriateposition to demand firing of a spark plug 143. Of course, there will beone spark plug for each cylinder of the engine 23 and the circuit shownin FIG. 6 is that associated with only a single cylinder of the engine.It should be understood that there will be corresponding circuits foreach of the spark plugs of the engine 23. However, it should also beunderstood that other ignition circuits than that illustrated may beused in conjunction with the invention.

The spark plug 143 is in circuit with a secondary winding of a sparkcoil 144. The primary winding of the coil 144 is in circuit with thecharging capacitor 114 and is adapted to be discharged to ground throughan SCR switch 145 under the control of a circuit energized by the pulsercoil 138. A trigger signal from the pulser coil 138 is transmittedthrough a diode 146 and capacitor resistor circuit 147 to the gate ofthe SCR 145 so as to turn it on and cause the capacitor 141 todischarge. This discharge through the primary winding of the spark coil144 will cause a voltage to be induced in the secondary winding whichwill fire the spark plug 143 in a known manner. A diode 148 is placedbetween the ground and the connection of the coil 137 to the diode 142for providing a circuit during the negative half wave of the chargingcoil 137. A similar diode 149 is provided between the capacitor 141 andthe primary of the spark coil 144 and the ground.

A master ignition control switch 151 is provided for grounding thecircuit to disable the ignition system when the operator wishes toswitch the engine 23 off. As has been noted, this portion of theignition system may be considered to be generally conventional and formsno part of the invention.

As has been noted, a device is incorporated for reducing the runningspeed of the engine 23 when the warning condition exists and thelubricant in the delivery tank falls below the line 79. This speedreducing system is effective to cause the spark plugs 143 not to befired for increasing time intervals during a given period of time sothat the spark plugs 143 will only fire once every several revolutionsof the engine until the speed is reduced to a level wherein theconsumption of lubricant will be substantially reduced. The speedreducing device includes a wave form shaping circuit 152 that receivesthe outputs from the pulser coil 138 and generates a square wave formpulse from them. This pulse is transmitted to a frequency to voltageconverter 153 that provides an output voltage V_(n) that is indicativeof the engine speed. When the terminal 135 is energized, an input willalso be provided to an oscillation circuit 154 which receives an inputfrom the frequency to voltage converter in the form of the signal V_(n)from the converter circuit 153.

Closure of the circuit including the terminal 135 also causes power tobe delivered through a diode 155 to a delay circuit 156 which has anoutput V_(r) that is also delivered to the oscillator circuit 58. Thetime delay circuit 156 operated like a capacitor in that its outputsignal V_(r) decays along a curve as shown in FIG. 7 once the terminal135 is energized by the closure of the switch 76.

The oscillator circuit 154 has an output voltage V_(a) that is generatedfor a time period that is varied in accordance with the differencebetween the voltages V_(n) and V_(r). The output of the oscillatorcircuit 154 is shown on the bottom line curve of FIG. 7 wherein theoutput extends for a period T₁ during a preset time interval T. As maybe seen from this figure, the time T₁ continues to increase until thevoltage V_(r) has decayed to the point T₁ at which it is constant andfor a fairly substantial time period. During the time T₁ when theoscillator 154 is providing its output, the firing of the spark plugs143 will be disabled.

This disabling is achieved by providing a shunting circuit that preventscharging of the capacitor 141. This shunting circuit includes an SCR 157that has its output connected to ground via a resistor 158. The SCR 157has its gate controlled by a gate circuit 159 that receives the outputfrom the oscillator circuit 154 and which energizes the gate of the SCR157 for a time T₁ as set by the oscillator circuit 154. An LED 161 isalso provided in the circuit from the SCR 157 with an interposedresistor 162 so as to provide a flashing indication that the ignition isbeing disabled to reduce the engine speed.

It should be noted that the time P1 is effective to stop firing of thespark plug 143 for a given time interval during a given time period.Hence, the spark plug 143 will not fire for each revolution of theengine and the engine speed will, accordingly, be reduced so as toreduce the consumption of lubricant from the delivery tank 32 so as toafford further protection.

The normal operation of the system as the lubricant is depleted fromboth the storage tank 31 and delivery tank 32 is, therefore, that firstthe green on light 103 will be illuminated until the level in thestorage tank 31 falls. At this time, the green light 103 will beextinguished and the yellow caution light 104 will be illuminated. Whenthe switch 76 is closed due to the low lubricant level in the deliverytank 32, the yellow caution light 104 will be extinguished and the redwarning light 105 and buzzer 106 will go on. However, during theabnormal situation that the level in the storage tank 31 is at or higherthan the level 45, the switch 57 will be closed and the green on light103 will be illuminated at the same time that the red warning light 105is illuminated. This will provide the operator with an indication thatthere has been a failure in the system connecting the storage tank 31with the delivery tank 32 since there is low lubricant in the deliverytank 32, but sufficient lubricant in the storage tank 31. This may occureither due to failure of the pump 36, its driving motor 39 or rupture ofone of the interconnecting connections. Therefore, the device alsoprovides a troubleshooting function.

Embodiment of FIGS. 10 and 11

In the previously described embodiment, the engine 23 was lubricated bydelivering all of the lubricant to the runners of the intake manifoldserving each of the crankcase chambers. Although such a lubricationsystem may be very adequate, in some instances, it may be desirable toprovide more lubrication to certain components of the engine than toothers or to specifically lubricate some components in a differentmanner than others. FIGS. 10 and 11 show an embodiment wherein suchdifferent lubrication delivery is achieved. Since the main controlsystem and delivery of lubricant to the lubricant delivery tank 32 isthe same in this embodiment as in the previously described embodiment,these components have not been illustrated again in any significantdetail nor will they be described again. In accordance with thisembodiment, the crankshaft 87 is supported between a cylinder block 201and a crankcase 202 in a generally known manner as by means of spacedmain bearings 203, 204 and 205. The bearings 203, 204 and 205 may be ofdifferent types such as ball bearings in the case of the bearing 205,roller bearings in the case of bearings 203 and 204. Various other typesof bearing arrangements may be employed.

The engine 23 of this embodiment, like the engine of the embodiment ofFIGS. 1 through 9, is depicted as being of the V4 type. Thus, connectingrods 206 interconnect pistons 207 with the respective throws of thecrankshaft 87. The crankcase chamber defined between the cylinder block201 and crankcase 202 is divided into separate vertically spaced sealedchambers 208 which communicate with each of the respective pistons 207through transfer passages in a known manner. These chambers are sealedfrom each other and a further chamber 209 is provided above the chamber206 and adjacent the bearing 203. A seal 211 surrounds the crankshaftabove the bearing 203 so as to seal the chamber 209. In a similarmanner, a chamber 212 encircles the bearing 204 and is sealed from theadjacent chambers 208. A lower chamber 213 is positioned between thelowermost of the crankcase chambers 208 and the bearing 205. The drivegears 85 and 86 for the lubricant pump 33, which is the same as theembodiment of FIGS. 1 through 9, is located within this lowermostchamber 213. Again, a seal 214 encircles the crankshaft 87 so as to sealthis lower chamber.

As with the previously described embodiment, the oil pump 33 has aplurality of outlets, each of which serves a respective conduit 215 thatdischarges lubricant under pressure into a respective runner of theintake manifold 29. As with the previously described embodiment, thereis one such conduit 215 for each manifold runner or each crankcasechamber 208. Thus, the rod bearings in the chambers 208 will belubricated by the lubricant that is delivered into the induction systemfor entry into the chambers 208 through the manifold 29.

In addition, the lubricant pump 33 has a further discharge conduit 216that delivers to a lubricant distributor 217. The lubricant distributor217 has a plurality of discharge outlets 218, 219, 221, 222 and 223. Theoutlets 218, 219 and 221 through 223 may be supplied with lubricant atthe same or different pressures, depending upon the components to belubricated and other design factors.

The conduit 218 supplies a fitting 224 that communicates with a passage225 formed in the cylinder block and terminating at the bearing 203.Thus, the conduit 218 lubricates the bearing 203 with the excess oilbeing delivered to the chamber 209.

The conduit 219 serves a fitting 226 which communicates with a passage227 in the crankcase 202 which terminates at the bearing 204 so as tolubricate this bearing. The excess lubricant is delivered to the chamber212.

The conduit 221 terminates at a fitting 228 which opens directly intothe crankcase chamber 213 so as to lubricate the lubricating pump drivegears 85 and 85 and also the lower main bearing 205.

The conduit 222 terminates at a pair of fittings 229 that are disposedin the cylinder block 201 and may either extend into areas adjacent thebores of the cylinders in which the pistons 207 reciprocate or,alternatively, may terminate within the transfer passages that transferthe fuel/air charge from the respective chambers 208 to the area abovethe pistons 207.

The conduit 223 terminates at a fitting 231 that may be utilized tolubricate any other component of the engine and, for example, mayterminate in a separate passage in the intake manifold 29 so as toprovide further lubricant to one of the runners.

Embodiment of FIG. 12

In the embodiment of FIGS. 10 and 11, certaion components of the enginewere lubricated at one pressure by the lubricant pump 33 and othercomponents were lubricated at different pressures through thedistributor 217. Rather than utilizing the lubricant pump 33 to supplyall of the lubricant, some lubricant may be supplied to certaincomponents of the engine either by gravity flow or by suction. FIG. 12illustrates such an embodiment.

In this embodiment, the lubricating points, and specifically thefittings 224, 226, 228, 229 and 231 are the same as in the embodiment asFIGS. 10 and 11 and their description and the components lubricated bythem will not be repeated. In this embodiment, the lubricant pump 33also delivers lubricant to the individual runners of the intake manifold29 through the conduits 215 as in the previously described embodiments.

In addition, a lubricant outlet fitting 251 is formed in the lower endof the delivery tank 32 and supplies a plurality of conduits thatdeliver oil to the respective fittings in a manner to be described. Thisdelivery will be partially under gravity and partially as a result ofthe negative pressures exerted at the various fittings under certainrunning conditions. If desired, appropriate check values may bepositioned at the respective fittings so as to prevent pressurization ofthe various lines under reverse pressure conditions.

A line 252 extends from the fitting 251 to the fitting 224 so as tolubricate the upper main bearing. A line 253 extends to the fitting 228to lubricate the lower main bearing and oil pump drive gears 85 and 86.A line 254 extends from the fitting 251 to the fitting 226 so as tolubricate the intermediate main bearing. A line 255 extends from thefitting 251 to the fitting 229 so as to lubricate the cylinder walls,piston and piston rings. A line 256 extends to the fitting 231 so as todeliver lubricant to it and the components which are lubricated by it.In all other regards, this embodiment is the same as those previouslydescribed and for that reason, further details of the already describedconstructions will not be repeated. Where components are the same asthose previously described, they have been identified by the samereference numerals.

Embodiment of FIGS. 13 Through 16

As has been noted, in connection with outboard motors, it is extremelydesirable, if not essential that the arrangement be such so as to afforda compact overall configuration. FIGS. 13 through 16 show an embodimentwherein the components are all located in such a way as to achieve acompact arrangement. In these figures, many of the components are thesame as those illustrated in conjunction with the previously describedembodiments and where this is the case, those components have beenidentified by the same reference numerals and their construction andoperation will not be repeated, except insofar as may be necessary tounderstand the invention as applied to these figures. The constructionand operation of the separate lubricating system is substantially thesame as that as the previously described embodiments and for thatreason, the construction and operation of these components will also notbe described again in detail, except insofar as to explain theorientation of these components.

An outboard motor constructed in accordance with this embodiment isidentified generally by the reference numeral 301. The motor 301includes a power head 302 that includes an internal combustion engine ofthe two-cycle type. The engine 302 is, as has been aforenoted, of the V4type and includes a cylinder block 201 that defines a pair of cylinderbanks 303 and 304. Cylinder heads 305 and 306 are affixed to thecylinder banks 303 and 304, respectively, in a known manner. Thecrankcase 202 extends from the V of the banks 303 and 304 so that theengine 302, when viewed from above, has a generally "Y" shape with arecess 307 formed between the bank 303 and the crankcase 202 and arecess 308 formed between the bank 304 and the crankcase 202.

Contained within the recess 307 and carried by the cylinder bank 303 isa control box, indicated generally by the reference numeral 309, thatmay contain such components and the ignition unit, electrical controlsand various other components associated with the engine 302 or theoutboard motor 301, per se.

Also contained within the recess 307 and carried primarily by thecrankcase 202 is the throttle, spark advance and transmission controlmechanism which encompasses an area shown by the dot-dash line 311 inFIG. 16. This includes an operator controlled throttle link 312 that isconnected to a cam and operator mechanism 313 that is journalled on thecrankcase 202 and which controls a first linkage 314 that is connectedto the throttle valves of the carburetors 26 in a known manner. Inaddition, a linkage 315 connects the control 313 to the mechanical sparkadvance of the engine. A transmission control link 316 is supported inthis area and operates the forward/neutral/reverse transmission of thelower unit of the outboard motor 301 in a known manner. This linkagearrangement for controlling the throttle, spark advance and shiftmechanism of the transmission may be of any conventional configurationand is described only so as to show how it may be located compactlywithin the surrounding protecting cowling of the outboard motor withoutadding unduly to the space requirements.

A further number of components are contained within the cavity 308defined by the cylinder bank 304 and the crankcase 202. These includethe lubricant delivery tank 32, lubricating pump 33 and its throttleoperated control. In addition, an electric starter 317 is provided inthis cavity and is adapted to cooperate with the flywheel 318 of theengine 302 for achieving electric starting in a known manner. Thisportion of the engine also mounts an engine driven fuel pump 319 thatreceives filtered fuel from the tank 28 by means including a fuel filter321. It should be readily apparent, therefore, that a relatively compactconstruction is achieved and yet one which facilitates servicing of thevarious components.

Embodiments of FIGS. 17 Through 19

As has been previously noted, it is desirable to provide a ventingsystem for the lubricant delivery tank 32 so as to insure that air canenter and leave the tank to compensate for changes in the level oflubricant therein. As was also noted, the fact that the outboard motoris adapted to be tilted up and steered requires positioning of theseventing means in such an arrangement that lubricant cannot be dischargedfrom the delivery tank 32 through the venting means when the motor istilted up. In connection with the embodiment of FIGS. 1 through 9,spillage from the delivery tank 32 when the motor is tilted up isprecluded by having the vent valve 83 disposed to admit air to thedelivery tank 32 and the vent valve 82 serves to discharge air from thedelivery tank 32. This valving relationship is employed since the valve83 will be the lowermost of the two valves when the motor is tilted up.Thus, its inherent position will tend to preclude the discharge oflubricant from the delivery tank 32 over such tilting up conditions.FIGS. 17 through 19 show various other venting arrangements wherein suchspillage during tilting up operation is avoided.

Referring first to FIGS. 17 and 18, the general construction of thedelivery tank 32 and its internal components, including the sensor unit65, is the same as the previously described embodiments and, for thatreason, these components will not be described again in detail. Thedelivery tank 32 is provided with a raised portion 351 at its rear endthat defines an air cavity 352 above the uppermost level of lubricantindicated by the line 77. A forwardly facing air inlet vent valve 353 isprovided in the raised portion 351 and a sidewardly facing outlet airvent valve 354 is provided in one of its sidewalls. The vent valves 353and 354 are designed so as to permit the flow of air into and out of thecavity 352 upon predetermined pressure variations. As shown in FIG. 18,these valves are disposed relative to lines LL and RR so that lubricantcannot pass from either of them when the engine is tilted up about itshorizontally extending tilt axis and regardless of its steered positionabout the vertically extending steering axis. The line RR indicates thelubricant level on a filled delivery tank 32 when the engine is tiltedup and steered to its extreme right-hand position. The line LLillustrates the corresponding condition when steered to the full leftlock. Therefore, it should be apparent that the likelihood of lubricantleakage is substantially precluded.

The likelihood of leakage can be even furtherimproved if the internalportion of the cavity 352 is provided with a horizontally extending airbaffle 355 which leaves only a small gap 356 through which the cavity352 may communicate with the lubricant in the tank 32.

FIG. 19 illustrates another embodiment of baffling arrangement. In thisembodiment, the venting valves are located in the same location;however, the cavity 352 is closed by means of a cover plate 361 fromwhich a baffle plate 362 extends. The baffle plate 362 leaves only anarrow annular gap 363 through which the cavity 352 may communicate withthe area above the lubricant the tank 32.

SUMMARY

It should be readily apparent that a variety of embodiments have beenillustrated and described, each of which provides an effectivelubricating system that has particular utility with outboard motors andwhich will insure against motor damage and yet allow long cruisingintervals. The invention has been described in conjunction with engineshaving V4 arrangements; however, it should be readily apparent that manyfeatures of the invention may be used in conjunction with engines havingother cylinder configurations or, in fact, other than reciprocatingengines. Also, the warning system as illustrated and described has manyadvantages; however, many of the features may be used in conjunctionwith other types of electrical warning systems than those disclosed.Various other changes and modifications may be made, without departingfrom the spirit and scope of the invention, as defined by the appendedclaims.

What is claimed is:
 1. In a lubricating system for a two-cycle internalcombustion engine for an outboard motor adapted to be supported forsteering movement about a generally vertically extending axis andtilting movement about a generally horizontally extending axis, saidlubricating system comprising a lubricant delivery tank carried by theengine and moveable about said axes with said engine, and means fordelivering lubricant from said delivery tank to the engine lubricationsystem, the improvement comprising venting means in said delivery tank,said venting means being positioned above the level of lubricant in saiddelivery tank in all the tilted and steered position of the outboardmotor.
 2. A lubricating system as described in claim 1 wherein thedelivery tank is provided with a recessed area defining a cavity in itsupper surface and the venting means communicates with said cavity, saidrecessed area being sealed except for said venting means.
 3. Alubricating system as described in claim 2 further including bafflemeans for restricting the communication between the cavity and theremainder of the delivery tank.
 4. A lubricating system as described inclaim 1 wherein the venting means comprises first check valve means foradmitting air only to said delivery tank and second check valve meansfor only discharging air from said delivery tank, said first check valvemeans being at a lower level than said second check valve means whensaid engine is tilted up.
 5. A lubricating system as described in claim1 further including a relatively large lubricant storage tank positionedremotely from said outboard motor and means for transferring lubricantfrom said storage tank to said delivery tank to maintain a predeterminedlevel therein.